title: Selection of obese patients undergoing ambulatory surgery: a systematic review of the literature.
abstract: BACKGROUND
  The incidence of obesity has increased over the past 2 decades. In recent years, several studies have assessed perioperative outcomes in obese patients undergoing ambulatory surgery. However, this evidence has not been reviewed and evaluated systematically.
  
  
  METHODS
  We conducted a systematic review of studies published between 1948 and May 2012, assessing perioperative outcome in adult obese patients undergoing ambulatory surgery. All studies were eligible for inclusion if they reported perioperative complications including unplanned hospital admission and readmission.
  
  
  RESULTS
  A literature search revealed 23 studies (13 prospective and 10 retrospective), and 1 systematic review assessing laparoscopic bariatric surgery. A total of 106,119 patients were included in the analysis with 62,476 patients included in the prospective trials and 43,643 patients included in the retrospective trials (not including the systematic review of laparoscopic bariatric surgery). Of these, 39,548 patients underwent bariatric surgery. The super obese (body mass index [BMI] >50 kg/m) appear to be at higher risk of complications. Patients undergoing nonbariatric surgery had a lower degree of obesity (BMI approximately 30 kg/m). Patients undergoing bariatric surgery were morbidly obese (BMI >40 kg/m), which is associated with a higher comorbidity burden. However, the lack of increase in unanticipated admission rate in this patient population may be related to thorough preoperative assessment and avoidance of patients with comorbid conditions.
  
  
  CONCLUSIONS
  The literature lacks adequate information to make strong recommendations regarding appropriate selection of the obese patients scheduled for ambulatory surgery. The literature does indicate that the super obese (BMI >50 kg/ m) do present an increased risk for perioperative complications, while patient with lower BMIs do not seem to present any increased risk as long as any comorbidities are minimal or optimized before surgery. This review also identifies knowledge gaps and recommends future research required to guide optimal selection of obese patients scheduled for ambulatory surgery.
authors.affiliation: From the *Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, Texas; †Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; ‡Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada; §Ambulatory Surgery Division, Hospital Corporation of America, Austin, Texas; and ‖Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Girish P
authors.initials: GP
authors.lastname: Joshi
authors.forename: Shireen
authors.initials: S
authors.lastname: Ahmad
authors.forename: Waleed
authors.initials: W
authors.lastname: Riad
authors.forename: Stanley
authors.initials: S
authors.lastname: Eckert
authors.forename: Frances
authors.initials: F
authors.lastname: Chung
mesh_terms: D000556:Ambulatory Surgical Procedures / Q000379:methods*; D050110:Bariatric Surgery / Q000379:methods*; D015992:Body Mass Index; D015897:Comorbidity; D005260:Female; D006801:Humans; D010535:Laparoscopy / Q000379:methods; D008297:Male; D009765:Obesity / Q000601:surgery*; D010359:Patient Readmission; D018579:Patient Selection; D059035:Perioperative Period; D011183:Postoperative Complications; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D016896:Treatment Outcome